The AMSOIL paper is far from being unbiased. Any time a manufacturer does an "unbiased" test and they conveniently test out as the best product, one should question their results. i.e., did they hand pick the competition's products, did they show "all" the results,did they hand pick the tests.

For example: Pennzoil and Valvoline came out poorly on these tests. Why did AMSOIL pick these particular products to test out of all the gear lube products both manufacturers make.

All of these tests are extreme tests and are far and away more severe than any conditions you are likely to encounter in everyday driving. When was the last time you towed a heavy trailer up a mountain on a 100 degree day.

I am not saying the report is false, I'm just saying that a paper put out by the other gear lube manufacturers may have shown different results.

"Figures don't lie, but liars figure". Take the results with a grain of salt.

 

I don't bother with studies like that... I won't even think about it when I'll go buy my oil this weekend!